Device for dispensing flowable substances

ABSTRACT

A device for dispensing flowable substances which includes an elongated housing having a chamber between a front discharge opening and a rear end opening, a piston rod axially longitudinally displaceable in the housing, an applicator at a forward end of the piston rod so as to be projectable out of the housing through the front end and retractable into the chamber with forward and rearward displacement of the piston rod, a dosaging piston disposed in the chamber and opening and closing the front discharge opening with rearward and forward displacement of the piston rod, a sealing face on the piston rod displaceable into sealing engagement with the rear opening when the piston rod is displaced rearwardly, a coupling element supported on a rearward end of the piston rod, and a closing cap removably disposed on the front end of the housing so as to close the chamber, and being disposable on the coupling element.

BACKGROUND OF THE INVENTION

The invention relates to a device for dispensing flowable substancesfrom a pencil-shaped housing comprising a displaceably mounted controlmember with which a discharge opening for the substance can be closedand which includes an applicator disposed in a retracted position withina chamber of the housing which is closed by a removable cap and fromwhich the applicator can be advanced. Flowable substances that can beused in this device are understood to be coloring liquids as they areused for make-up. This includes liquids for application onto the skin aswell as those to be applied to the finger or toe nails. Depending on theintended use, these liquids may have widely varying viscosities. Inaddition, the device is also intended for use with other liquids, suchas, for example, adhesives or solvents. The applicator is preferably abrush; however, fiber wicks or capillary tubes known from writingimplements can also be employed.

A dispensing device for flowable substances, such as, for example, nailpolish, is known (U.S. Pat. No. 4,063,829) in which an applicator in theform of a brush is advanced from a chamber disposed in the front sectionof the container. The brush is fastened in a slidable member providedwith axial grooves through which a predetermined quantity of theflowable substance is supplied to the brush by the force of gravity. Inthe operating position of the brush, i.e. when it is oriented verticallydownwardly, a ball valve blocks the further advance of liquid. For useof the dispensing device, before the cap is removed, the container mustbe held upright for a moment so as to fill the dosaging chamber. Afterremoval of the protective cap, the dispensing device must be rotated insuch a manner that the tip is directed downwardly. This causes the brushand the slide member to move within the chamber until the brush projectsfrom the chamber and the slide member seals off the majority of thechamber, leaving narrow channels as the only connection between thebrush and the interior of the dosaging chamber. Once the brush has beenmoistened with the liquid, it is ready for use. As soon as the measuredquantity of liquid transferred to the brush has been used, the devicemust be tilted again to permit a new quantity of liquid to be suppliedby way of the dosaging chamber.

Proper operation of this dispensing device is assured only if the ballvalve as well as the slide member and the brush are able to move underthe force of gravity.

Particularly for the use of nail polish it is necessary to permit suchpolish to dry shortly after it has been applied. For this reason, thesepolishes contain very volatile solvents which may, however, dry just asquickly within the dispenser.

In one device of the type described above, in which the movable partsare moved only by gravity and supported by acceleration forces generatedby shaking the device, it may happen that the parts stick together andno longer move freely. Then the dispenser no longer functions properly.Designs of this type have therefore been unable to displace from themarket the conventional nail polish bottles in which the brush isattached to the screw closure.

The already mentioned nail polish bottles employing brushes are known tohave the drawback that during application with the brush the bottle isnot closed. Thus, the liquid contained therein not only may easily dryup or thicken, there also exists the danger that the bottle may betipped over and the liquid run out. To avoid this drawback, dispensingdevices are known in which the applicator is not connected with thescrew closure but is inserted directly into the container. According toWest German Utility Model DE-GM No. 79/31,006, a container for nailpolish is known which is equipped with an applicator brush at the mouthof the container. The bristles of the applicator brush are fastened to amovable head piece which is provided with channels and which can beretracted at least partially into the mouth of the container against theforce of a spring element and in which the closing cap is provided withmeans for sealing the mouth of the container. If now the closing cap ofthis container is removed, the brush moves out of the head section ofthe container under the action of the spring. The container is nowimmediately exposed to the ambient air, possibly causing the liquid todry out or thicken.

Summary of the Invention

It is the object of the invention to reduce, in a dispensing device forflowable substances, the influx of air into the interior of thecontainer to a minimum and to arrange its manipulation so that it isimpossible to inadvertently permit air to enter. It must not be possiblethat removal of the closing cap already permits liquid to flow out ofthe interior of the container unless the dispenser is being used for itsintended purpose.

To accomplish this task, the invention configures a device fordispensing flowable substances of the above-mentioned type in such amanner that the applicator is disposed at one end of a piston rod whichis axially longitudinally displaceable within the housing. The other endof the piston rod is provided with a coupling element to which theclosing cap can be coupled once it has been removed from the frontsection. Providing a second seat for the closing cap prevents thedispenser from being inadvertently left open, thus permitting air topenetrate into the interior of the container. The user always needs thereseatable closing cap, so as to place it onto the coupling element andthus be able to use the device.

The reseatable closing cap may be of simple design. It may have aconical interior configuration adapted to the outer shape of the frontsection and of the coupling element. Thus there is only one matingsurface on which the cap can be placed.

Improper operation of the dispenser can be avoided if the couplingelement is made axially displaceable in a recess in the housing. Only ifthe cap is attached, which then projects from a recess, can the devicebe used.

In one embodiment, the device has such a configuration that a chamber isprovided which has openings at opposite frontal faces, with displacementof the piston rod alternatingly opening and closing the opening orientedtoward the supply tank by means of a sealing surface and the openingoriented toward the discharge bore by means of a dosaging piston, andthe blocking piston is elastically deformable.

Thus, the supply tank employed in the device according to the inventionis advantageously sealed against the external air in both end positionsof the piston rod-even if the closing cap is removed. A furtheradvantage is that the pressure exerted on the substance in order tocause discharge is absorbed without additional parts exclusively by theelastic configuration of the blocking piston. If the dosaging piston ismoved into the chamber, the compression spring builds up this pressurewhich, although it drops when the dosaging piston leaves its bore, issufficiently high to prevent external air from entering into thedosaging chamber. The supply tank itself is hermetically sealed again inthe rear end position of the dosaging piston so that air is preventedfrom entering there as well.

As already mentioned, no air must enter into the chamber and into thesupply tank when the piston rod and the dosaging piston with its sealingsurface are between their two end positions. And liquid must beprevented from escaping when the dosaging piston remains between the twoopposing openings. To prevent this it has been found to be advantageousfor a shaft to follow the dosaging piston, with such shaft, between thetwo end positions of the piston rod, forming an annular capillary gapwith the opening oriented toward the discharge bore.

Preferably, the volume of the chamber is smaller than the volume of thesupply tank accommodating the flowable substance. In this way it isassured that the capillary forces in the annular gap behind thedischarge bore are sufficiently high to prevent the substance fromrunning out even if the device is in a vertical position.

To permit easy and machine assembly of the chamber in the supply tank, atwo-part embodiment is provided in which the chamber is composed of asleeve whose one front wall has an opening faced by a disc also havingan opening. The smooth movement of the device can be influenced bystepping up the travel of the blocking piston in that the diameter ofthe dosaging piston is made significantly smaller than that of theblocking piston. The costs for individual parts can easily be reduced inthat the dosaging piston not only produces pressure in the chamber andin the container but additionally acts as a valve. This can be realizedby making the effective length of the dosaging piston shorter than thedistance from the disc to the front wall of the chamber.

Operational reliability of the device depends essentially on theblocking piston performing several different functions. A good seal mustbe produced at the outer diameter and in the bore of the hub, whichrequires form stability. On the other hand, the piston must be able toabsorb the volume of the substance displaced by the pressure, withoutescaping toward the rear end of the device. With the required stabilityof the piston this is assured due to the fact that the blocking pistonis elastically deformable at least in the partial region whichconstitutes the piston base. The rigid configuration of the hubadvantageously also serves to support the blocking element, for whichpurpose the blocking piston is provided with a thin blocking disk at anextension of the hub. The outer diameter of this blocking disk isgreater than the diameter of the inner wall of the supply tank. Thenumber of individual parts can be reduced in that the piston rod and thedosaging piston are made of one piece with the sealing surface and thelatter is molded onto a valve ring which supports a compression spring.The differences in diameter between the dosaging piston and the blockingpiston permit influencing the stroke of the dosaging piston. Due to thefact that, at the side of the dosaging piston oriented toward thedischarge bore, a shaft is disposed which supports an applicator andthis applicator, in its starting position, is completely retracted inthe discharge bore under the influence of the compression spring, theapplicator can be moved out of the discharge bore to the optimum extentfor use. Distribution channels formed in a partial region of thedischarge bore permit good wetting of the applicator.

A further advantage results from a coupling element fastened to thepiston rod with which a closing cap can be coupled once it has beenremoved from the front section. In this way, it is assured that the useris able to use the device only if the closing cap has been placed ontothe rear section of the container.

Increased ease of operation of the device results from the featureswherein capillary channels are formed in a ring having a slope, and theapplication can be retracted into the discharge bore of the conicalfront section by means of the coupling element. Within the chamber andon the dosaging piston, guide, switching and detent elements areprovided which permit the applicator to be locked in the advancedposition against the force of a spring. Pressure on the closing capunlocks and retracts the applicator, similar to a ball point penswitching mechanism. By configuring the chamber as a switching sleeve, aswitching mechanism as basically disclosed in West German AuslegeschriftDE-AS No. 1,239,591 can be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in greater detail below with referenceto the drawing. It is shown in:

FIG. 1, a longitudinal sectional view of the device with the closing capapplied;

FIG. 2, a longitudinal sectional view with the closing cap placed on theother end;

FIG. 3, a cross-sectional view along line I--I of FIG. 6;

FIG. 4, a cross-sectional view along line II--II of FIG. 6;

FIG. 5, a longitudinal sectional view of an improved embodiment with thecap attached;

FIG. 6, a longitudinal sectional view of the same embodiment with theclosing cap at the other end;

FIG. 7, a partial sectional view of the valve piston of FIG. 6;

FIG. 8, a view along line I--I of FIG. 6;

FIG. 9, a view along line II--II of FIG. 6;

FIG. 10, a longitudinal sectional view of a further embodiment employingan additional control disk;

FIG. 11, a view along line III--III of FIG. 10;

FIG. 12, a sectional view of the ring on the piston rod;

FIG. 13, a longitudinal sectional view of the device with the applicatorretracted;

FIG. 14, an enlarged view of a region of FIG. 13;

FIG. 15, a sectional view along line I--I of FIG. 13;

FIG. 16, a sectional view along line II--II of FIG. 13;

FIG. 17, a longitudinal sectional view of the device of FIG. 13;

FIG. 18, a longitudinal sectional view of the device of FIG. 13 with thedosage piston in its forward position;

FIG. 19, a longitudinal sectional view of the device in accordance withanother embodiment of the invention;

FIG. 20, a partial sectional view of the switching mechanism of FIG. 19to an enlarged scale;

FIG. 21, a cross-sectional view of the switching mechanism along lineIII--III of FIG. 19;

FIG. 22, a developed view of the operational section of the switchingmechanism of FIG. 19; and

FIG. 23, a longitudinal sectional view of the device of FIG. 19 with theclosing cap on the rear end and the applicator advanced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The illustrated apparatus is composed of a housing 1, whose frontsection 2 is conically tapered and includes in this region a chamber 3ending in channels 4 toward the interior of the container. A seal 7 isinserted into an end wall 5 forming a recess 6 therebehind. A cup-shapedinsert 8 is provided with a plurality of discharge openings 9 and guidewebs 10. This insert 8 is pressed into housing 1. A closing cap 11comprising an internal frustoconical surface 12 and a bead 13 is placedonto front section 2. Centered in housing 1, a piston rod 14 is disposedso as to be axially longitudinally movable and a control piston 15 isseated on piston rod 14 so as to be displaced with friction. Thelongitudinal travel of piston rod 14 is rearwardly limited by crosspieces 16 which, if piston rod 14 is made of plastic, may be moldeddirectly to it.

Additionally, a coupling element 17 is fastened to piston rod 14 inrecess 6, with its outer face being adapted to the inner frustoconicalsurface 12 of closing cap 11. Piston rod 14 also includes an applicator18, preferably a brush. A flowable substance 19 fills the interior ofhousing 1.

The device, which is shown in the rest position in FIG. 1, ishermetically sealed at its front end by closing cap 11. Influx of airfrom the other side is prevented by seal 7. To apply the flowablesubstance with the device, it is initially necessary to remove closingcap 11 from conical front section 2 and place it onto coupling element17. This inevitably advances piston rod 14 toward the front untilcontrol piston 15 places itself against the mouths of channels 4. Duringfurther longitudinal movement of piston rod 14, applicator element 18advances out of chamber 3. Since in the meantime control piston 15 hasplaced itself against channels 4, their cross section is reduced. If thedevice is held in a vertical position, substance 19 is now able to passthrough discharge openings 9 and, due to the predetermined cross sectionof channels 4, is supplied to applicator 18 in such a manner that thequantity of substance 19 corresponds approximately to the quantityrequired for normal use.

When not in use, cap 11 is removed again from coupling element 17; thiscauses piston rod 14 to be moved toward the rear until control piston 15again seals discharge openings 9. Applicator 18 returns to chamber 3 sothat cap 11 can be placed onto front section 2 without damagingapplicator 18.

The device shown in FIGS. 5 and 6 is composed of a container 20 whosefront section 2 is conically tapered and includes, in this section, adischarge bore 21, a cylindrical space 22 and a widened chamber 3changing to a bore 24. Bore 24 ends in a front wall 25. The connectionto the interior of container 20 is formed by openings 26 between whichguide webs 27 are disposed and surrounding a guide bore 26a for thepiston rod 14 (See FIG. 8). The interior of container 20 is terminatedat the rear by transverse wall 28 provided with a guide bore 29.Following transverse wall 28, a recess 30 is formed by an extension ofcontainer 20. To seal discharge bore 21 at the frustoconical frontsection 2, a cap 11 is provided which has at least one innerfrustoconical surface 31.

Piston rod 14 is mounted in guide bore 29 so as to be axially movable.At one end, piston rod 14 is provided with a coupling element 17 whichcan be brought to rest against a compression spring 32. Referring alsoto FIG. 7, valve piston 33 having a plurality of molded-in axial grooves34 is also disposed on the pistonrod. A diaphragm 35, supported by arearwardly facing, rearwardly and radially inwardly sloping face ring 37having a 38, lies against frontal face 36 of valve piston 33. At itsfront end, the piston rod is provided with an applicator 18 which may bea felt tip, a brush or a rounded section of piston rod 14. A blockingpiston 40 is mounted on piston rod 14 so as to be axially displaceableand sealed. This blocking piston places itself against the inner wall ofcontainer 20 and has a blocking disk 41 fastened to it which ispreferably made of steel and has a plurality of radial slits 42. See FBlocking disk 41 is supported at the inner wall of container 20; in thedisassembled state, it is a disk which has a diameter larger than theinner diameter of container 20.

FIGS. 10 and 11 show a further embodiment in which blocking piston 40does not include a blocking disk 41. This blocking piston 40 restsagainst the interior wall of the container with greater friction thanagainst piston rod 14, thus permitting piston rod 14 to move withoutdisplacing blocking piston 40. In the region of frustoconical frontsection 2, an annular chamber 43 is formed in container 20 toaccommodate a control disk 44 which is movable with a friction fit onpiston rod 14. This control disk 44 can thus be placed against a planarrear face 45 formed at wall 46. When piston rod 14 is displaced, controldisk 44 can also be brought to lie against a planar frontal face 47 intowhich open overflow channels 48. (See FIG. 11) In this embodiment, theapplicator is a discharge channel 49 through which substance 19 flowsout.

FIG. 12 shows a detail of ring 50 which, as in the embodiment of FIGS.5-9 has a sloping rear face 51. To better distribute the flowablesubstance 19 pressed out by valve piston 33, capillary channels 52 areprovided which have a reduced cross section so as to form a capillarygradient in the direction toward applicator 18.

Mode of Operation

The front of container 20 filled with flowable substance 19 is sealed,according to FIG. 5, with a cap 11. To operate the device, cap 11 mustinitially be removed and placed onto coupling element 17. This movespiston rod 14 toward the front and together with it, valve piston 33which thus exposes openings 26. Now, substance 19 is already able toexit from the interior of the container since a slight suction force isproduced by valve piston 33. This suction force, however, is interruptedas soon as valve piston 33 reaches chamber 3 which has a larger diameterthan diaphragm 35. Due to the length of chamber 3, it is thus possibleto advance the piston rod and push applicator 18 out of discharge bore21. If, during the further advance of piston rod 14, valve piston 33enters into cylinder 22, diaphragm 35 places itself against the frontalface of valve piston 33 blocking grooves 34 and produces a seal with theresult that a subatmospheric pressure is generated which causes furtherflowable substance 19 to be sucked out of the interior of the container.During movement of valve piston 33 within cylinder 22, coupling element17 abuts on compression spring 32. At the end of the movement ofcoupling element 17 which is charged by cap 11 being placed on it,compression spring 32 pulls piston rod 14 back again as soon as there nolonger is any pressure on coupling element 17. During the returnmovement of piston rod 14, valve piston 33 presses against flowablesubstance 19 which has now filled chamber 3. Substance 19 thuspenetrates into axial grooves 34, tilts diaphragm 35 forward and finallyflows in the direction toward applicator 18 or into discharge channel49. The quantity to be discharged is given by the path of spring 32during its compression, while the dosaging process and the discharge ofsubstance 19 takes place under the influence of the decompressing spring32.

Thus, during each dosaging process, piston rod 14 is initially displacedforward and then moved back again under the action of compression spring32. The discharged quantity of flowable substance 19 is thus determinedby the path of blocking piston 40 which follows substance 19, supportedby the suction effect, the adhesion forces and ultimately by gravity. Toprevent return of blocking piston 40, the blocking disk 41 is providedwhose function, however, can also be performed by the control disc 44shown in FIG. 10. During the return travel of piston rod 14, controldisk 44 places itself against a planar face 45 and thus closes openings26. In the reverse direction, during advance of piston rod 14 and duringsucking in of flowable substance 19 by means of valve piston 33 and itsdiaphragm 35, control disk 44 places itself against planar frontal face47 with overflow channels 48 permitting passage of substance 19.

With the aid of the above-described device, it is thus possible totransfer measured quantities of flowable substances 19 having differentviscosities to an applicator 18 or to press them out of a dischargechannel 49.

Applicator 18, which can be retracted into cylindrical space 22 offrustoconical front section 2, is there not only protected in its restposition; it is also prevented from being damaged when cap 11 isapplied, which is of particular significance if a brush having softbristles is used as applicator 18. Moreover, placing applicator 18 incylindrical space 22 and chamber 3 has the result that, in its retractedstate, it is almost completely surrounded by substance 19 thussubstantially preventing the brush bristles from drying out. Whenapplicator 18 is advanced, it is thus already saturated with flowablesubstance 19 and ready for use. The only drying out occurs at the end ofdischarge bore 21 and applicator 18 is able to penetrate such driedportions without being damaged since applicator 18 fits very tightly indischarge bore 21.

FIG. 13, which is a longitudinal sectional view of another embodiment,and the enlarged sectional view of FIG. 15 show all parts of the devicein their starting positions. A cylindrical supply vessel 60 changes intoa frustoconical front section 2 and ends in a step 61. A discharge bore62 in the region of front section 2 has a plurality of distributionchannels 63 which open into a dosaging bore 64 followed by a bearingbore 65 which tapers toward inner wall 66 of storage vessel 60. A frontopening 67 is provided in a disk 68 which is held in a sleeve 69inserted into bearing bore 65. At an inner frontal face of sleeve 69,there is provided a front wall 70 having a further opening 71 whichbecomes frustoconical at 72 toward the interior of sleeve 69 and isprovided with additional guide webs 73. A blocking piston 74 composed ofa hub 75 and a sealing ring 76 connected with one another by means of apiston base 77 lies in the supply vessel with sealing ring 76 againstinner wall 66. A blocking disk 78 preferably made of metal and having adiameter, in the planar position, which is larger than the innerdiameter of supply vessel 60 measured at inner wall 66, is fastened tohub 75.

A piston rod 14 provided at its rear end with a coupling element 79 anda guide plate 80 is pushed through hub 75 of blocking piston 74. Withinsleeve 69 on piston rod 14 a frustoconical sealing face 81 is shaped toa valve ring 82, with this valve ring 82 being followed by a dosagingpiston 83 which changes into a shaft 84 in which an applicator 18 isfastened. Conventional felt tips are suitable as applicator 18 as theyare known from writing implements; preferred, however, is a brush as itis customary in the screw caps of nail polish bottles. A cap 85 servesto close discharge bore 62 and can be clamped to frustoconical frontsection 2, with step 61 retaining any flowable substance 19 possiblyescaping from discharge bore 62. Valve ring 82 and disk 68 serve asabutments for a compression spring 86, thus continuously pressing pistonrod 14 into the starting position shown in FIG. 13. The apparatus thusincludes two separate interior chambers, one of which, chamber 87, actsas the so-called dosaging chamber, while supply vessel 60 holdsavailable a supply of flowable substance 19.

The be able to transport flowable substance 19 from supply vessel 60 toapplicator 18, cap 85 is initially removed and placed onto couplingelement 79. Now it is possible to move piston rod 14 forward intodischarge bore 62 against the force of compression spring 86. It must beassumed that flowable substance 19 completely fills supply vessel 60 aswell as chamber 87 and is additionally already contained in at leastpart of distribution channels 63. Once sealing face 81 has been liftedaway from frustoconical opening 72, the movement of piston rod 14initially exposes rear opening 71. During further movement of piston rod14 in the same direction, dosaging piston 83 moves in chamber 87 untilit enters into front opening 67. As soon as this has taken place,further movement of dosaging piston 83 produces a subatmosphericpressure in chamber 87 as well as in supply vessel 60 with the resultthat blocking piston 74 continues to lie against flowable substance 19and thus moves in the direction toward discharge bore 62. If now,dosaging piston 83 has reached its forward position shown in FIG. 18,applicator 18 is in the operating position and can be used to applyflowable substance 19, to the extent that it is contained thereon. Oncethis substance 19 has been applied, applicator 18 must be retractedagain which compression spring 86 is able to do if no pressure isexerted on coupling element 79. If now dosaging piston 83 enters intochamber 87, pressure is generated there pressing substance 19 againstblocking piston 74. Since blocking piston 74 itself cannot move backwardalong inner wall 66, but is supported by blocking disk 78, the pressureis absorbed by the elastic deformation of piston base 77 as shown inFIG. 17. The pressure increases as long as dosaging piston 83 moves intochamber 87. When, however, dosaging piston 83 leaves opening 67 in disk68, the pressure is able to be reduced through opening 67. This isaccomplished by the elasticity of piston base 77 which again takes onits position shown in FIG. 13. During reshaping of piston base 77, apredetermined quantity of substance 19 is pressed out of opening 67 intodosaging bore 64 and into distribution channels 63. The retractedapplicator 18 is now also disposed in the region of distributionchannels 63 and is there resupplied with flowable substance 19. Ifapplicator 18 is then pushed out of discharge bore 62, substance 19 canagain be applied.

The device according to the embodiment of FIGS. 19 to 23 has anelongated member which is longitudinally movable in the device housingand includes a piston rod, a valve ring, a dosaging piston and a shaft,and; operates according to the same principle as the embodimentaccording to FIGS. 13 to 18, but with the difference that applicator 18can be fixed in the operating position against the force of compressionspring 86. For this purpose, a switching sleeve 90 is inserted intosupply vessel 60 and is provided with an opening 92 in its frontal face91 and with a plurality of ribs 94 on its inner wall 93. A switchinggroove 95 and a stop groove 96 are alternatingly formed between ribs 94,with stop groove 96 being less deep than switching groove 95 and endingin a sloped supporting face 97. Ribs 94 end at sloped abutments 98 andhave the same slope angle as supporting faces 97. Switching cams 99having a lateral slope 100 are provided on valve ring 101 which is madeof one piece with a piston rod 102. Dosaging piston 83 attached to thefront end of valve ring 101, which is identical with the embodiment ofFIG. 13, further supports a rotatably mounted switching cross 103 (FIG.20) provided with a plurality of switching cams 104 having slopes 105.The number of switching cams 104 on switching cross 103 is only half thenumber of switching cams 99 on valve ring 101.

When cap 85 is placed onto coupling element 79, piston rod 102 can beaxially displaced to bring flowable substance 19 to applicator 18 andput it into the operating position. Switching cams 99 disposed on valvering 101 are thus guided in switching grooves 95 and stop grooves 96,while switching cams 104 at switching cross 103 lie exclusively inswitching grooves 95 and are there moved axially. If now switching cams104 (FIG. 22) leave switching grooves 95, switching cross 103 turns,with corresponding slopes 100, 105 sliding on one another. After leavingslope 100, slope 105 is initially pressed by the force of compressionspring 86 against sloped abutment 98 and then slides onto supportingface 97 at the end of stop groove 96. Thus, switching cross 103--whichhas turned --is detained at this point and supports compression spring86. Thus applicator 18 can no longer be set back into discharge bore 62by the force of compression spring 86, as is the case in the embodimentaccording to FIG. 13.

To set applicator 18 back, piston rod 102 must be pushed through untilswitching cams 104 of switching cross 103 lift away from supporting face97 and slide over the adjacent rib 94. Due to the sloped abutment 98,switching cams 104 are moved into switching grooves 95. Compressionspring 86 is now able to return dosaging piston 83 to its startingposition and thus close opening 92.

What is clamed is:
 1. A device for dispensing flowable substances, comprising:an elongated housing having a front end, a rear end, a chamber and a supply vessel rearward of said chamber, said front end having a discharge bore forward of said chamber and a front end opening forward of said discharge bore, said chamber having a front face and a rear face at respective opposite longitudinal ends thereof, said front and rear faces respectively having front and rear openings therein, said chamber respectively communicating with said discharge bore and said supply vessel through said front opening and said rear opening; an elongated member having a forward end and a rearward end and axially longitudinally displaceable in said housing, said elongated member having in said chamber a sealing face facing said rear face, which alternately closes and opens said rear opening with rearward and forward displacement of said elongated member, and a dosaging piston facing said front face, which alternately opens and closes said front opening with rearward and forward displacement of said elongated member; a cylindrical switching sleeve in said housing forming said chamber therein, said sleeve having axially longitudinally extending circumferentially spaced ribs along a part thereof and stop grooves and switching grooves alternately disposed between said ribs; a valve ring fixed to said elongated member in said sleeve having first switching cams longitudinally axially displaceable in said switch grooves and said stop grooves; a switching cross confronting said valve ring and surrounding said elongated member in said sleeve, having second switching cams axially longitudinally displaceable in said switch grooves, said cross being displaceable axially beyond switching grooves in said sleeve, said cross being rotatable in said sleeve when beyond said switching grooves, the number of said first switching cams being twice the number of said second switching cams; and an elastically deformable blocking piston on said elongated member at a rear end of said supply vessel opposite said rear opening of said chamber.
 2. A device as in claim 5, further comprising a compression spring, said elongated member, said dosaging piston and said sealing face having a one piece construction, said elongated member further including a valve ring having said sealing face molded thereon, said compression spring being disposed on said elongated member and supported at one end on said compression spring by said valve ring.
 3. A device as in claim 2, wherein said compression spring is supported at another end of said compression spring opposite said one end by said front face of said chamber.
 4. A device as in claim 1, wherein said switching grooves and said stop grooves have different respective radial depths, said stop grooves terminating in sloped supporting faces.
 5. A device for dispensing a flowable substance, comprising:a. a longitudinally elongated housing having a front end and a rear end, said housing including(1) a dosaging chamber, (2) a supply vessel for storing a quantity of the flowable substance, rearward of said chamber, (3) a discharge bore in said front end, forward of said chamber, and (4) a front end opening, opening to the exterior of the housing forward of said discharge bore; said chamber having a front face and a rear face at respective opposite longitudinal ends thereof, said front and rear faces respectively having front and rear openings therein, said chamber respectively communicating with said discharge bore and said supply vessel through said front opening and said rear opening; b. a longitudinally elongated member having a forward end and a rearward end and being axially longitudinally displaceable in said housing, said elongated member having(1) a sealing face disposed in said chamber and facing said rear face, said sealing face alternately closing and opening said rear opening with rearward and forward displacement of said elongated member, (2) a dosaging piston disposed in said chamber and opening and closing said front opening with rearward and forward displacement of said elongated member, and (3) a shaft on a forward end of said dosaging piston so as to project into said discharge bore through said front opening, said shaft having a lesser diameter than a diameter of said front opening; c. an applicator mounted to said a forward end of said shaft so as to be displaceable with rearward and forward displacement of said elongated member outward of said front end opening and into said discharge bore; and d. an elastically deformable blocking piston on said elongated member at a rear end of said supply vessel opposite said rear opening of said chamber sealing said supply vessel against the rearward escape of the substance therefrom, said elongated member being longitudinally movable with respect thereto, such that a longitudinal movement of said elongated member with said shaft in said front opening causes a predetermined amount of the substance to pass through said front opening into said discharge bore to be retained by said applicator.
 6. A device as in claim 5, further comprising:a coupling element supported on said rearward end of said elongated member; and a closing cap removably disposed on said front end of said housing so as to close said front end opening and disposable on said coupling element.
 7. A device as in claim 5, wherein said shaft and said front opening define therebetween an annular capillary gap when said elongated member is between opposite end positions respectively in which said sealing face closes said rear opening and said dosaging piston closes said front opening.
 8. A device as in claim 5, wherein said chamber has a volume smaller than the volume of said supply vessel.
 9. A device as in claim 5, further comprising:a sleeve in said housing having said chamber therein, said sleeve having a frontal wall having said front opening therein, and a disk facing said sleeve, having said rear opening therein.
 10. A device as in claim 9, wherein the distance between said dosaging piston and said sealing face is less than the distance between said disk and said frontal wall.
 11. A device as in claim 5, wherein said dosaging piston has a diameter substantially smaller than the diameter of said blocking piston.
 12. A device as in claim 5, wherein the distance between said dosaging piston and said sealing face is less than the distance between said front opening and said rear opening.
 13. A device as in claim 5, wherein said blocking piston has an inner portion engaging said piston rod, an outer portion engaging said housing and an elastically deformable surface portion between said inner and outer portions which deforms so as to push the predetermined amount of the substance into said discharge bore when said elongated member is moved from the end position in which said dosaging piston closes said front opening to the end position in which the sealing face closes said rear opening.
 14. A device as in claim 5, further comprising a blocking disk having a diameter greater than an inner diameter of said supply vessel, said blocking piston being disposed between said blocking disk and said supply vessel and has a hub through which said elongated member extends, said blocking disk being fastened to said hub.
 15. A device as in claim 5, wherein said blocking piston has a hub engaging said elongated member, an outer portion engaging an inner wall of said supply vessel and an elastically deformable surface portion between said inner and outer portions, said hub having an extended portion behind said surface portion, said blocking piston having a blocking disk at said extended portion of said hub, said blocking disk being spaced from said elastically deformable surface portion and having a diameter greater than an inner diameter of said supply vessel.
 16. A device as in claim 5, further comprising a compression spring in said housing, said compression spring urging said elongated member in a rearward direction toward a starting position in which said applicator is completely within said discharge bore, said applicator being projectable against the force of said compression spring out of said discharge bore through said front end opening with forward displacement of said elongated member.
 17. A device as in claim 5, wherein said discharge bore has distribution channels in a partial region thereof, said shaft having a radially peripheral surface and being projectable into said partial region of said discharge bore so as to have said distribution channels at said radially peripheral surface.
 18. A device as in claim 5, further comprising a blocking disk having a diameter greater than an inner diameter of said supply vessel, wherein said blocking piston is disposed between said blocking disk and said supply vessel and has an inner hub portion engaging said elongated member and fixed to said blocking disk, an outer portion engaging said housing and an elastically deformable surface portion between said hub and said outer portion which deforms so as to push the predetermined amount of the substance into said discharge bore when said elongated member is moved from the end position in which said dosaging piston closes said front opening to the end position in which the sealing face closes said rear opening.
 19. A device as in claim 5, wherein said dosaging piston has a cylindrical outer surface of predetermined longitudinal extent and is partially extendable into said discharge bore while closing said front opening with longitudinl movement of said elongated member. 